This invention utilizes existing back-up collision avoidance sensors to provide an anti-pinch function for a liftgate or other closure at the rear of a vehicle.
Modern vehicles are often provided with collision avoidance systems at the rear of the vehicle that can sense a foreign object in the path of the vehicle as the vehicle moves rearwardly. As an example, ultrasonic sensors are positioned along the rear bumper of a vehicle, and send out a signal rearwardly of the vehicle when the vehicle is moving in reverse. These sensors can detect an object behind the vehicle, and communicate with a display in the cab of the vehicle to provide a warning of the existence of the object.
Also, many vehicles are provided with a liftgate, tailgate, or other closure for the rear of the cab of the vehicle. All of these rear closures will be referred to generically as a liftgate for purposes of this application.
Such rear closures are often power closed by a motor driving an element to close the closure. The known liftgate systems will often include an anti-pinch algorithm, which monitors an electrical characteristic of the motor such as current or voltage. If this electrical characteristic provides an indication that an object is in the path of the closing liftgate, then further movement of the liftgate may be stopped or reversed. This prevents pinching when a person, such as a child, is in the path of a moving liftgate. While known anti-pinch algorithms are quite beneficial, they still do require actual contact between the object in the path of the liftgate and the liftgate. It would be desirable to provide an anti-pinch arrangement that does not require actual contact.
In a disclosed embodiment of this invention, the known back-up detectors are utilized when a liftgate is being moved to the closed position. If the back-up detectors detect the presence of an object in the path of the liftgate, then the motor for the liftgate is stopped, preventing the liftgate from further closing. Thus, the object will be detected prior to the liftgate contacting the object and the liftgate will not close to contact the object.
The present invention thus provides benefits in not requiring actual contact between the object and the liftgate. Further, the integration of a single sensor to provide both functions reduces the number of components that must be incorporated into the vehicle.
While the present invention is most preferably utilized in a power liftgate system to stop a motor, it is also within the scope of this invention that a manually closed liftgate could have some blocking feature to block closing movement of the liftgate should an object be detected in the path of the liftgate.
These and other features of this invention can be best understood from the following specification and drawings, the following of which is a brief description.